How do you convert a string to a function in python?

Question

How do you convert a string (for example, input from a textbox) into a proper function?

Answer 1

You can use eval. But be very careful! This opens up lots of security holes.

>>> s = '3+4'
>>> eval(s)
7

If you want it callable:

>>> s = '3+4'
>>> f = eval('lambda: ' + s)
>>> f()
7

More information on eval here.

Answer 2

try this

func = ___import___('func_name')

or

if hasattr(your_module, func_name): func = getattr(your_module, func_name)

or

if func_name in globals(): func = globals[func_name]

or something etc

Answer 3

def func():
 print "hello"
# just eval it
eval(raw_input())
# if you just want to ask for name
fName=raw_input()
if fName in globals():
 globals()[fName]()

And there could be various other ways depending on what is the objective?

• nickf: hi anurag, just for a little beginner experiment - get the user to type a function and then i graph it
• Anurag Uniyal: in that case I think eval would be just fine, you can use pycallgraph.start_trace() (pycallgraph.slowchop.com) before eval